On Some Problems of Mateescu Concerning Subword Occurrences
Cunsheng Ding, Arto K. Salomaa · Rare & Special e-Zone (The Hong Kong University of Science and Technology) · 2006
The paper investigates inference based on quantities \W\_u, the number of occurrences of a word u as a scattered subword of W. Parikh matrices recently introduced are useful tools for such investigations. We introduce and study universal languages for Parikh matrices. We also obtain results concerning the inference from numbers \W\_u to W, as well as from certain entries of a Parikh matrix to other entries.